code: def test_unique_keys_no_overlap_exception(self):
      hmap1 = HoloMap(
          {i: Curve(range(10)) for i in range(5)}, kdims=["A"]
      )
      hmap2 = HoloMap({i: Curve(range(10)) for i in range(3, 10)})
      exception = (
          "When combining HoloMaps into a composite plot "
          "their dimensions must be subsets of each other."
      )
      with self.assertRaisesRegex(Exception, exception):
          dims, keys = unique_dimkeys(hmap1 + hmap2)
  
file_path: holoviews/holoviews/tests/core/test_traversal.py
imports: from holoviews import Curve, DynamicMap, HoloMap
  from holoviews.core.traversal import unique_dimkeys
  from holoviews.element.comparison import ComparisonTestCase
label_desc: Use image node_id 3 for calling the TestUniqueDimKeys obj's underlying member method code with example usage: obj.test_unique_keys_no_overlap_exception() without return types